“Aufbaureaktion” which was first reported by Ziegler in 1952, discloses inserting ethylene into an aluminum carbide bond, and imparting long-chain trialkylaluminum. This technique is used for industrial production of straight-chain alkene (Alfen process) and straight-chain alcohol (Alfol process).
As mentioned above, the Alfol process is known as an industrial method for producing straight-chain higher alcohol (e.g., see Non-Patent Document 1). A typical reaction would be reacting triethylaluminum (AlEt3) with high pressure (120 Kgf/cm2) ethylene at 120° C. (following reaction formula (1)), and then oxidizing at 50° C., 5 Kgf/cm2 (following reaction formula (2)) and hydrolyzing at 90° C. (following reaction formula (3)) to convert to alcohol.Al(C2H5)3+3nC2H4→Al[—(CH2—CH2)n—C2H5]3  Reaction formula (1):
Here, in reaction formula (1), n represents any integer.Al[—(CH2—CH2)n—C2H5]3+1.5O2→Al[O—(CH2—CH2)n—C2H5]3  Reaction formula (2):
Here, in reaction formula (2), n represents any integer.Al[O—(CH2—CH2)n—C2H5]3+3H2O→3C2H5(CH2CH2)nOH+Al(OH)3  Reaction formula (3):
Here, in reaction formula (3), n represents any integer.
Consideration on performing the Alfol process in an ethylene pressure available in the laboratory has already been made, and it has been confirmed that if the reaction of AlEt3 is performed in an ethylene pressure of 20 Kg/cm2, the yield of the objective straight-chain alcohol is about 3% of the applied aluminum compound which is extremely low when the reaction temperature is 120° C., and when the reaction temperature is increased, the production of straight-chain terminal alkene becomes the main reaction (see comparative experiment). In general, in order to obtain an aluminum compound intermediate from the above reaction formula (1) by inserting ethylene in between Al—C of AlR3 (R=Me, Et), it is necessary for the reaction to be carried out under an ethylene pressure of 80 to 300 Kg/cm2 and a high temperature (at least 100° C. or higher).
Meanwhile, a technique for obtaining an aluminum compound intermediate that is the same as the product of reaction formula (1) under low ethylene pressure (e.g., about 5 Kg/cm2) is known. This method called Catalytic Chain Transfer Polymerization (CCTP method) enables converting an R group (R=Me, Et) of a main group metal alkyl (e.g., AlR3, ZnR2, MgR2) into a long-chain alkyl through the reaction with ethylene, by using a transition metal alkyl compound as a catalyst. By using the obtained AlR3 (R: long-chain alkyl), it is possible to obtain alcohol R—OH in accordance with formulas (2) and (3) (e.g., see Non-Patent Documents 2 and 3).
However, since the above-mentioned CCTP method proceeds in a mechanism where the ethylene insertion takes place between the transition metal and alkyl, and then the grown alkyl group causes exchange with an alkyl group bonded to aluminum, there is a problem that before the long-chain alkyl transfers to aluminum, terminal alkene mixes in due to side reactions that cause β-hydrogen elimination on the transition metal. In addition, regardless of whether the interaction between alkyl aluminum and transition metal alkyl is strong or weak, the objective reaction will not proceed, and therefore there is a problem that the reaction conditions are limited (e.g., see Non-Patent Document 2).